In pre-contact Hawaiʻi, a lūʻau meant a lavish meal of foods grown in the ahupuaʻa, which extended from the mountain to the sea. From the land came ʻuala (sweet potato), kalo (taro), ʻulu (breadfruit), niu (coconut), and meats cooked in an imu (underground oven). From the sea came iʻa (fish), limu (seaweed), and delicacies like wana (sea urchin) and ʻopihi (limpets) found in the intertidal zones on rocky shorelines.
Hānau ka Makaiauli, o ka ʻOpihi kana keiki, puka – born was the big limpet, his child the small limpet came forth. This line from the Kumulipo, the Hawaiian origin chant, recognizes the interconnectedness of the unpretentious ʻopihi to the Hawaiian people from the beginning of time. Non-native foods have been added to the lūʻau menu over the years, but ʻopihi has never lost its status as a prized dish at family parties.
Like other foods gathered or cultivated in ancient Hawaiʻi, ʻopihi was very much a part of the subsistence diet, especially for people who lived along the shoreline. The ʻopihi’s rough edges and sturdy shells made them additionally useful as scraping tools. Where ʻopihi weren’t readily available, such as on sandy leeward shores or up mauka (inland), they might be brought in from another ahupuaʻa that had a more rugged coastline and where they grew in abundance. Their value was further increased by the danger often encountered while prying the tasty mollusks off rocks pounded by crashing waves.
Similar to the management of other ocean resources, ʻopihi picking was traditionally overseen by the konohiki, or manager of the ahupuaʻa, who was knowledgeable about when, where, and how much of the resource could be harvested without harming the populations. The konohiki system gave way to the pressures brought on by westernization and an increasing demand on resources as the population and commercial markets for local products grew.
Although ‘opihi reproduce every six months and grow quickly without any controls over their harvest, their populations became decimated during the twentieth century. “Instead of having one graduation party for a community every summer, we have, like 500,” says Pelika Andrade, an education and community engagement specialist at the University of Hawaiʻi Sea Grant College Program (Hawaiʻi Sea Grant). “Every marriage wanted ʻopihi at their party and it no longer mattered that we had less; it mattered that it had to be part of the venue.”
“You can say it’s overharvesting, but I just think it’s too much people, and it’s not getting better,” says Pekelo Lind, a lifelong fisher and ʻopihi picker from Kīpahulu. “You notice that when there’s no parties, there’s a lot of ʻopihi. Then three, four months before the parties, ʻopihi is getting wiped out left and right.”
To curb the decreasing ʻopihi populations, in 1981 the State of Hawaiʻi Department of Land and Natural Resources (DLNR) adopted an Administrative Rule prohibiting the sale of ʻopihi smaller than 1.25 inches with shell attached, or less than 0.5 inches for meat only. The rule also mandated that a permit would be required to sell ʻopihi. Despite these regulations, ʻopihi populations continued to decline. Overharvesting, too many people, and the high market cost of ʻopihi, which likely encourages illegal gathering and unpermitted sales, all contribute to the dwindling ʻopihi population.
For the past fifteen years, Hawaiʻi-based scientists have been looking for other reasons for the decreasing populations. Many of their studies have focused on the ecology and reproductive cycles of ʻopihi and have shown that overharvesting is only one of the variables that have led to their decline. Their research has shown that habitat is a critical factor in maintaining healthy ʻopihi populations. These scientists support shifting from statewide ‘size’ rules to community management as a more effective way to protect and regulate ʻopihi harvests and their habitats. In other words, create a management style that would be a modern day konohiki-type system, based on ʻōiwi (Indigenous) Knowledge.
Pelika Andrade is one of the Native Hawaiian scientists who have been studying ʻopihi habitats. Hard substrate is a prerequisite for ʻopihi to grow, but she cites other factors that drive productivity: cliff versus shelf beaches; leeward versus windward; high wave impact versus protected shorelines; and shadow versus direct sunlight, such as on parts of the Napali coast of Kauaʻi and Nihoa Island, in the Northwest Hawaiian Islands.
“When you don’t have sunlight for four months, the food source [for the ʻopihi] goes away, which makes for an unstable habitat,” Andrade explains. “All these drivers are important to understand, and when we talk about habitat, it has to be in context of the season.”
In addition to looking at habitat as a critical determinant of productivity, size has also come into question as an appropriate gauge for harvesting ʻopihi. Kanoe Morishige, a PhD candidate in marine biology at the University of Hawaiʻi at Mānoa, has studied the shell remnants of ʻopihi found in archaeological digs. “There’s a lot to learn from the sizes of ʻopihi that were collected. I’m sure our kupuna ate the smaller ʻopihi as well as the bigger size, and that’s an important part of the subsistence practices, that they know exactly which ones to harvest.”
Understanding the carrying capacity of a habitat explains why smaller ʻopihi would be harvested as well. “When you have 100 percent cover, some people say ʻthat’s amazing’, but it’s really bad,” Andrade noted. “There’s a balance of being able to take some ʻopihi off, to allow new genetics and new recruitment, but just taking enough off where we’re not jeopardizing the habitat.”
Dr. Anthony Mau, the general manager at Kupu Place Aquaponics, is part of this group of scientists who have been studying ʻopihi, not only to understand their biology and habitat better, but also the future implications of global warming on the mollusks. There are four endemic species of ʻopihi in Hawaiian waters: ʻopihi makaiauli (blackfoot) which reside above the tidal zone; ʻopihi ālinalina (yellowfoot) which live in the intertidal zone; ʻopihi koele (kneecap) that live completely underwater; and the green-foot limpet, which live primarily in the intertidal zone in the Northwestern Hawaiian Islands. Mau focused his research on ʻopihi ālinalina as it is considered the tastiest and therefore the most sought-after and vulnerable to overharvesting.
Mau and his colleagues were able to create a life history curve for the five-year life span of individual ʻopihi, which had never been done because of the difficulty and danger of accessing ʻopihi in their intertidal habitat. Their curve shows how temperature and seasonal changes influence the growth rates of the ʻopihi over time.
“The big takeaway is that they don’t grow at the same pace throughout the year,” says Mau. “They basically don’t grow when it’s super cold and it’s super rough. They stop growing again during periods of high temperatures.”
This becomes especially relevant when considering an increase in ocean temperatures, whether due to climate change or human factors. “The temperature of the ocean surrounding Oʻahu is consistently warmer than that of other islands for a variety of reasons: less fresh water input to the ocean because of all the fresh water consumption by large amounts of humans, habitat degradation, effluent water pumped into the ocean, even from the lights at night,” says Mau.
He did another study on the diet of ʻopihi in aquaculture and had an outcome he didn’t expect. When the ambient temperature hit 83.3 degrees F, which is an average Oʻahu sea surface temperature in summer, their health started to degrade, and there were significant levels of mortality. This observation prompted Mau to note that “ʻopihi in Oʻahu waters are living at the threshold band of temperatures that they can tolerate. And what will it be like when we move into a warmer climate, as Hawaiʻi becomes more tropical instead of subtropical?”
Mau and his colleagues hope that their work will shed light on the shortcomings of the information on which ʻopihi regulations are based. “The paradigm shift is you need to actively manage,” says Mau. “We think you can harvest the smallest size possible. We’ve tracked the data, and it shows that through natural loss, you can have a population that’s massive in density; then, it drastically shrinks down because of environmental constraints. If you trim the fat at the right time, before the rest of the environment gets to it, then that can be a food source that is sustainable.”
Some communities have been experimenting with more active management strategies. In 2014, community groups in East Maui reintroduced the traditional practice of creating rest zones for ʻopihi makaiauli along the Kīpahulu Moku, based on voluntary compliance. In 2015, the DLNR adopted a rule creating the Hāʻena Community-Based Subsistence Fishing Area on Kauaʻi, which limits the harvest per person per day to 20 ʻopihi. Luna Kekoa, who is the ecosystem management program manager at the State of Hawaiʻi Division of Aquatic Resources, says his department is open to working with communities on management plans, including harvesting smaller size ʻopihi.
“That’s kind of how we’re seeing the future. It will be place-based,” says Kekoa. “When it’s the community [managing], people are supportive and respectful, because it’s the people of the place.”
While Native Hawaiians Morishige, Andrade, and Mau are all trained in western science, their approach to research has been through an ʻōʻiwi (native) lens, that is based on customary and ancestral practices.
“We’re seeing certain things about fisheries management that just don’t align with the goals we’re trying to get, in terms of not just blaming everything on overharvesting, but trying to help communities understand the environmental conditions that allow ʻopihi to thrive,” says Morishige. “We are trying to pay attention to our environment, how things have changed, and weave the past and present to build our knowledge so we can get to a place where our ʻopihi and our intertidal ecosystem thrive and continue to feed us.”
Browse Ka Pili Kai issues HERE